442 
Supplement to the “ Tropical Agriculturist.'" [Dec. 1, 1897. 
in large doses of 100 c.c., but that, immunity 
conferred was only “passive in its nature and 
temporary in its effects.” In order, tlierefore, 
to increase the immiini-iug power of the serum, 
and at the same time reduce the necessity for 
so large a dose, he added to it 1 per cent, of 
rinderpest blood. This mi.tture acted more 
sati.sfactorily, but at that time he con,=idered 
that it was neither .so safe nor so effective as 
the mill obtained from sick animals. Con- 
temporaneously experiraeiits with serum were 
conducted conjointly by the chief veterinary 
sm-o-eons, Mr. Fitchford, of Natal, and Mr. 
Tbeller of Transvaal, on similar linei. Since 
then Drs. Danysz and Bordet, the French scientists, 
have devoted' their attention principally to the 
perfection of the serum method of treatment 
both as a preventive and curative agent. As 
they express it, “ their main object was to procure 
a serum which could be successfully applied to 
a herd in which the disea.se had already made 
its appearance, and where the em;d -.ynmut of 
methods which brought on the dise i.-j in a light 
decree could only aggravate the condition of 
the animals already affected, and the le^rults 
of their numerous e.xperiments show that this 
object has bean attained. 
With respect to the manner in which herds 
inoculated with serum should be treated, they 
say: “It is known that the blood of salted 
oxen does not give permanent immunity from 
rinderpest, but that animals injected with this 
blood acquire the property for a limited time 
of withstanding the attack of the disease more 
easily. If they are brought in contract with 
rinderpest after the injection with blocd, they 
contract the disease but recover, and become 
salted. When the animals are already sick, or 
if they already possess the germs of rinderpest 
at the moment of injection, nothing else remains 
to be done chan to inject blood to make the 
dimase less serious for them. On the other 
hand the animals that are not affecte I by rinder- 
pest ’at the moment of injection must become 
infected so tliat they can catch the disease in 
a liaht’form which the blood will help them 
to rt'et through, but which is also sufficient to 
thoroughly sTilt them. Kinderpest can be trans- 
mitted eit'her by allowing the animals to mix with 
sick oxen, or by injecting rinderpest blood, and it 
must be known which of the two means is the 
better We are convinced from the trials thac 
infection solely and exclusively developed through 
rinderpest blood cannot be regarded as good, 
as it is impossible— within the range of our 
knowledge— to apply it in practice in such a 
maimer as to obtain good results.” 
From the foregoing it will be ob.served that 
the principil advance which Drs. Danysz and 
Bordet have made in the application of the serum 
treatment to rinderpest consists in the method 
which they have devised for communicating the 
infection to the serum-inoculated cattle; so that 
they contract a modifted from of the disease 
from which thev recover and become .salted. 
Other scientists,‘buti)rincipally Semmer, Nencki, 
Sieber and Wyznikievvicz, had previously dis- 
covered that the serum of animals which have 
recovered from the pest has immunising properties, 
but these experts trusted to repeated injections 
of the serum while the anim ils were liable to 
the disease rather than to one large injection 
followed by immediate exposure to infection, 
£0 that the inoculated aniniil should contract 
a mild form of the disease at once, under the 
modifying effects of the serum, from which they 
would recover. This is the most important point 
in Drs. Danysz and Bordet’s application of the 
serum method of treating rinderpest. 
It has to be noted, howe'er, that these French 
e.xperts do not con-ider the serum treatment so 
suitable for dealing with clean Icrds as with 
herds already infected, or herds which can be 
exposed to infected animals immidiately and 
continuously afterinoculation. T’hey say: “The 
injection of small quantities of rinderpest blood 
into animals that have been previously inoculated 
with the blood of s ilted animals is not sufficient 
to infect a beast in such a degree as to secure 
for them a continuous salting after the cure. 
To attain a goad result a cirefullj' 
regulated ipiintity of blood must be injected, 
large enough to occasion a small degree of sick- 
ness, small enough to guard against serious sick- 
ness or death. But the correct meisureof such 
a quantity of infected blood cannot be deter- 
mind in practice, as it depends on how much 
strength the preventive blood previ msly injected 
possesses. Two samples of preventive blood 
never have the same strength. . . . It huppena 
differently wdth animals which have received an 
injection of preventive blood, and coming into 
contact with animals infected with rinderpest 
immediately afterwards. Such animals always 
get an attack of rinderpest, which is not deadly, 
when the preventive blood used is good, but which 
is sufficient to w ell salt the beast.” Further, 
if healthy animals which have been inoculated 
with preventive blood or serum are exposed to 
infected cattle immediately and continuously 
afterwards, it is of little importance whether 
the dose of serum injected is unneces.sarilj'^ strong 
or not, so long as it is sufficiently strong to 
give complete immunity at the time ; because 
the subsequent infection being continuous each 
animal contracts a mild form of the disease as 
the strength of the immunity conferred bj^ the 
serum gradually admits. This cannot be accom- 
plished satisfactorily by an injection of rinder- 
pest blood, which has to be made at a deftnite 
time after the serum inoculation, because if the 
dose of serum is very strong the majority of 
the animals may resist the after-blood inoculation 
and manifest no signs of fever, and consequently 
will not become silted. On the other hand, 
should the dose of serum be comparatively 
weak, and the after-blood inoculation be too 
long delayed, the animals inoculated would be 
liable to contract a virulent form of rinderpest, 
from which many would die. 
In like manner if a healthy herd of cattle 
is in.oculatad with a strong dose of serum, and at 
the end of 2i hours they are driven in amongst an 
infected herd, and kept there from 12 to 24 
hours and then withdrawn, this has been found 
to give very unsatisfactory results, because during 
the slii rt exposure many of the inoculated cattle did 
not contract the disease but caught the infection 
subsequently from their companions (since the 
immunity had jiassed off by that time) and died of 
